This research article explains the effects of pH and metal composition on the selective calcium extraction from steel slag. The operating parameters including extraction solvent type, solvent concentration, metal composition of steel slag, substance type and pH were investigated. HCl, NHCl, NHOH and NaOH were employed as solvents to extract Ca from steel slag. It has been shown that hydrochloric acid effectively extracts Ca. The high metal content in steel slag reacted sensitively to the solvent concentration, and a specific concentration was derived to selectively extract Ca. The optimal solvent for calcium extraction was 2 M HCl, which induced the extraction of 97% of Ca; 46% of Mg; 35% of Al; and 1% of Si from the steel slag. In order to separate Ca in the leaching solution from other metal ions, various acidic/basic substances were added to regulate the pH. The optimal pH level for removing the impurities without calcium was found to be 9.5. The precipitated impurities were removed by filtration, and the pH was adjusted to 13 or higher for Ca(OH)(s) production. In conclusion, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) revealed that the Ca content produced through the process was more than 99%. It is expected that high-purity Precipitated Calcium Carbonate (PCC) will be achieved when the generated Ca(OH) is used as a source of calcium for mineral carbonation.
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http://dx.doi.org/10.1039/d0ra08497b | DOI Listing |
J Environ Manage
January 2025
Hebei Key Laboratory of Close-to-Nature Restoration Technology of Wetlands, School of Eco-Environment, Hebei University, Baoding, 071002, China; Engineering Research Center of Ecological Safety and Conservation in Beijing-Tianjin-Hebei (Xiong'an New Area) of MOE, China. Electronic address:
Waste activated sludge (WAS) pose a potential risk for the spread of antibiotic resistance genes (ARGs). This study estimated the effect of sludge on antibiotic resistance genes (ARGs) in anaerobic sludge digestion process. Metagenomic analysis revealed anaerobic sludge with potassium ferrate (PF) and the modified PF loaded steel slag (MPF-SS) brought an increase of ARGs during digestion process.
View Article and Find Full Text PDFIn this project, cement-based composites reinforced with slag powder (abbreviated as SP), steel slag powder (abbreviated as SSP), and desulfurization gypsum (abbreviated as FGD) were used as the research objects, and the preparation, mechanical properties, and strengthening mechanism of the composites were systematically studied. A laser particle analyzer (Malvern Instruments Analysis) was used to determine that the particle sizes of the raw SSP, SP, and FGD materials were concentrated between 5 and 40 μm, indicating that they were fine-grained minerals. SSP and SP are highly active alkaline substances.
View Article and Find Full Text PDFEnviron Monit Assess
December 2024
ICAR-Indian Institute of Seed Science, Mau, Uttar Pradesh, India.
The retention and mobility of arsenic (As) in soil depend on various physical and chemical factors. The knowledge of the sorption-desorption chemistry of As in soil is necessary for predicting the fate and behavior of As in soil environments. Therefore, this study assessed different organic (sugarcane bagasse and vermicompost) and inorganic amendments (steel slag and fly ash) for their impact on sorption-desorption of As in texturally different contaminated soils (of sandy clay (SC) and sandy clay loam (SCL) texture) to understand the effect of amendments on As retention and mobility.
View Article and Find Full Text PDFEnviron Res
December 2024
School of Civil Engineering, Dalian University of Technology, Liaoning Province, Dalian, 116024, China. Electronic address:
Alkaline-activation technology was an effective means of disposing of low-activity and heavy-metal-containing industrial solid wastes. In this paper, alkali-activated converter steel slag and municipal solid waste incineration fly ash (MSWIFA) were prepared by modulating alkali-activation conditions. The effect of alkali-activation conditions on microstructure of C-(A)-S-H and leaching of lead and zinc, pore solution pH, and the correlation among them were revealed.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Faculty of Materials Engineering, Silesian University of Technology, 40-019 Katowice, Poland.
Electric arc furnaces are commonly used in foamed slag technology for the production of steel from steel scrap through an electric process. The effects of using this technology include increased efficiency, reduced consumption of refractory materials, reduced energy consumption, reduced electrode wear, and improved arc stability. The world is constantly looking for solutions to optimize the feeding of the foaming agent to the electric furnace, including determining the moment of starting its feeding.
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